#region License
//-----------------------------------------------------------------------
// <copyright>
// The MIT License (MIT)
// 
// Copyright (c) 2014 Kirk S Woll
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// </copyright>
//-----------------------------------------------------------------------
#endregion

using System.Collections.Generic;
using WootzJs.Compiler.JsAst;

namespace WootzJs.Compiler
{
    public class JsMinifier : JsWalker
    {
        private int generatedNameCounter = 1;
        private Dictionary<string, string> generatedNames = new Dictionary<string, string>();

        private string Minify(string s)
        {
            string result;
            if (!generatedNames.TryGetValue(s, out result))
            {
                result = "$" + generatedNameCounter++;
                generatedNames[s] = result;
            }
            return result;
        }

        public override void Visit(JsVariableReferenceExpression node)
        {
            base.Visit(node);
            node.Name = Minify(node.Name);
        }
    }
}
